Inductive bond



Sept. 5, 1933.

S. M. LUCAS ET AL INDUCTIVE BOND Filed Aug. 15, 1952 hm W um,

5 Sheets-Sheet l 75 INVENTORS Jamuelflluoas and BY Q/RW 77/5112 ATTORNEY.

Sept. 5, 1933.

S. M. LUCAS El AL INDUCTIVE BOND Filed Aug. 15, 1932 3 Sheets-Sheet 2 O (15 r9 &

O Flgd IN VENTORS Samuel MLuoas and By Conrad H. Zif'dl.

THE/[Z A TTORNEY p 1933- s. M. LUCAS Er AL INDUCTIVE BOND Filed Aug. 13, 1932 3 Sheets-Sheet 3 AV Av AV &V AV

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IN VEN TORS Samuel M Lucas am, By 6012mm H Z (emit.

T [IE/12 A TTORNE Y Patented Sept. 5, 1933 UNITED STATES PATENT QFFICE INDUCTIVE BOND of Pennsylvania Application August 13, 1932. Serial No. 628,698

7 Claims.

Our invention relates to inductive bonds, and particularly to inductive bonds which are used in the trackway when an alternating current track circuit signaling system is applied to a 5 railway both rails of which are used for the transmission of current for propulsion purposes. More particularly, our present invention relates to improvements in inductive bonds of the type shown and described in Letters Patent oi the United States No. 838,916, granted to L. H. Thullen on Dec. 18, 1906.

We will describe one form of inductive bond embodying our invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a vertical sectional view showing one form of inductive bond embodying our invention. Fig. 2 is a top plan view, with cover removed, of the bond shown in Fig. 1. Fig. 3 is a sectional view or" the bond shown in Figs. 1 and 2 taken substantial- 1y on the line III-III of Fig. 2. Fig. 4 is a detail view showing one of the E-shaped stampings 11 which comprises the core 8 of the bond illustrated in the preceding views. Fig. 5 is a detail view showing one of the'angle brackets 14 forming part of the bond illustrated in Fig. 1. Fig. 6 is a detail view showing one of the terminal posts 29 forming part of the bond illustrated in Figs. 1, 2 and 3. Fig. 7 is a view of the post 29 shown in Fig. 6 rotated through an angle of substantially Fig. 8 is a top plan view of the main cover 2 forming part of the inclosing case for the bond illustrated in Figs. 1, 2 and 3. Fig. 9 is a top view of the auxiliary cover 2 forming part of the case for the bond illustrated in Figs. 1, 2 and 3.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1, 2 and 3, the inductive bond, which is designated as a whole by the reierence character A, is inclosed in a suitable case 1 provided with a two piece cover 2 which we will describernore fully hereinafter. The case 1 is adapted to be supporte on, and secured to, two adjacent ties 3 of a railway track, as shown in Fig. 1, and for this purpose, the case is provided on one side with a lug 4: which is apertured to receive a bolt or lag screw 5, and on the opposite side with two similar lugs 6 and '7, the lugs i, 6 and '7 being located as near the top of the case as possible in order to prevent any more of the case from extending above the level of the ties than is absolutely necessary.

The bond A, in the form 11 re illustrated, coinprises a three-legged closed core 8, the middle leg 9 of which is surrounded by a winding 15.

The core 8 is laminated for obvious reasons, and is preferably made up of E-shaped stampings 11, one of which is shown in Fig. These stampings are stacked with the openings therein facing in opposite directions and with their legs overlap- 0 ping, and are secured together by means of bolts 12 which extend through aligned holes in the stainpings, one bolt as here shown being located near each corner of the case and adjacent each end of the middle leg 9.

The winding 10 is similar to the winding B shown in Figs. 5 and 6 of the Thullen Patent No. 838,916 referred to hereinbeiore, and coinprises two parts or halves 10 and 10 each of which is in the form 01" an elongated spiral, the turns of one part being arranged between and insulated from the turns of the other part. The winding 19 is insulated from the adjacent parts of the core 8 by suitable insulation 13 which may, for example, be paper or fiber, and is securely clamped in place in the bottom of the core windows by means of two angle brackets 14, the vertical legs of which are each provided near the center thereof with an inclined slot 15 (see Fig. 5) through which one of the bolts 12 passes, thus providing a toggle and Wedge construction. By forcing these brackets sidewise in the proper directions, their horizontal legs may be forced against the insulation which surrounds the winding thereby forcing the winding to the bottom of the core windows; and if the nut on the bolt 12 which passes through these brackets is then tightened, the coil will be rigidly clamped against vertical movements relative to the core. Eniwise movement of the winding 10 is prevented by wooden blocks 16 (see Fig. 1) which are driven between the winding and the middle leg 9 of the core 8 on opposite sides of this leg. One advantage of the means just described for fastening the winding in place is that it positively prevents any motion of the winding with respect to the core in any direction in spite of the intense vibration to which the bone. is subjected due to passing trains. Wear on the isulation due to relative movements between the core and winding is therefore prevented which materially increases the life of the bond. Another advantage of this method of fastening the winding in place is that the parts are inexpensive to manufacture and are easy to assemble.

Secured to the opposite sides of the core 8 near the bottom of the core, by means of certain ones of the bolts 12, are two angle bars 17 which rest on suitable slotted lugs 18 provided on the base of the case 1. The angle bars 1'7 are apertured to receive the shanks of bolts 19, the heads of which bolts are held within the slotted lugs 18. Nuts 19 are screwed onto the upper ends of these bolts, and, when tightened, securely fasten the bond to the case. The detailed construction and arrangement of the lugs 18 is similar to that of the lugs 15 shown and described in Letters Patent of the United States No. 1,439,680, granted to H. A. Anderson and H. R. Smith on Dec. 26, 1922, for Impedance bonds, and need not therefore be described here.

The inner end of the part 1i)" of the winding 10 is connected, by means of a suitably shaped conductor 20 welded thereto, with a terminal structure T1 which is mounted in a hole 22 formed in the upper wall of the case 1 near the righthand end thereof, as viewed in Fig. 2, and the inner end of the part 10 of the winding 10 is likewise connected, by means of a suitable shaped conductor 23 welded thereto, with a terminal structure T2 which is mounted in a suitable hole 24 provided in the right-hand end wall of the case 1, as viewed in Fig. 2; while the outer ends of the parts 10 and 10 of the winding 10 are respectively connected, by means of suitably bent integral conductors 25 and 26 with the terminal structure T2, and with another terminal structure T3 which is mounted in a hole 27 formed in the right-hand end of the lower wall of the case 1, in alignment with the hole 22 in the upper wall, as viewed in Fig. 2. The terminal structures T1, T2 and T3 are similar, and a description of one will therefore sufflce for all three.

Referring now particularly to the terminal structure T2 shown in section in Fig. 1, the hole 24 in which this terminal structure is mounted is tapered and reamed as shown, and has seated therein a conicalinsulating bushing 28. A terminal post 29 (see Fig. 6) provided with a square head 29 at one end and a threaded portion 29 at the other end, connected by an integral intermediate portion 29 which is taperedto flt the hole in the bushing 28, extends through this bushing with its tapered portion in engagement with the bushing, and has screwed onto its threaded portion a clamping nut 30. Interposed between the clamping nut 30 and the adjacent surface of the case 1, in the order named, are a cupped spring steel washer 31, a plate washer 32, and an insulating washer 33. The insulating washer 33 acts in conjunction with the bushing 28 to insulate the terminal post 29 from the case, and the plate washer serves to distribute over the face of the insulating washer the pressure which is exerted by the cupped washer when the clamping nut is tightened to flatten the washer the desired amount. The pressure exterted by the cup washer when it is flattened will usually be between three thousand and ten thousand pounds, which keeps the assembly tight in spite of variations in temperature, and gives a non-turning eflfect to the assembly by forcing the tapered parts tightly together.

The threaded portion 29 of the terminal post is provided, in addition to the clamping nut 30, with another clamping nut 34 by means of which the apertured outer ends of the conductors 23 and 25 are secured to the terminal structure, and with a lock nut 35 which prevents the nut 34 from working loose.

Extending through a threaded hole 36 formed in the head 29 of the terminal post 29, at right angles to the axis of the terminal post, is a threaded stud 37, each end of which is provided with a clamping nut 38 and a lock nut 39. By means of this arrangement, two cables may be connected to the terminal post in such manner that one cable may be removed without disturbing the connection between the terminal post and the remaining cable. The stud 37 is locked against turning in the desired position within the hole 33 by a pin which is riveted in a hole 46 passing through the head and the stud.

The head 29 of the terminal post 29 is also provided adjacent its inner end with four rounded shoulders l0 which, when the terminal post is fastened in place, are separated from the case by air gaps, the lengths of which are less than the arcing distance from any other part of the terminal post to any part of the case, cover or core. These air gaps provide spark gaps which acts as a lightning arrester in a manner which will be made clear hereinafter.

One advantage of the terminal structure just described is that since the bushing 28 and insulating washer 33 are used in compression, the assembly is very rigid and strong mechanically. Another advantage of this terminal structure is that the case 1 is intended to be filled with a suitable cooling and insulating medium such, for example, as transformer oil, and the tapered fit between the parts forced into place by heavy pressure provides a tight seal, thus eliminating leakage of oil out of the case or seepage of water into the case.

The two piece cover 2, referred to hereinbefore comprises a main cover 2 (see Fig. 8) of substan- 1 tially the same shape and size as the top of the case 1, and an auxiliary cover 2 in the form of a ring around the main cover (see Fig. 9). The main cover is intended to seal the case to prevent oil from leaking out of the case and water from seeping into the case, and is securely clamped to a flange 41 formed at the top of the case by means of bolts 42, as will clearly be apparent from an inspection of Figs. 1 and 3. A gasket 43 of cork or other suitable material is preferably 1 provided between the flange 41 and the adjacent part of the cover to improve the seal. The bond can be installed without removing the main cover thus preserving the seal.

Formed on the main cover 2" edge of the case 1 is a depending rib 44 (see Fig. 1) which serves a drip edge to drip any oil which splashes against the cover hack into the case. The rib 44 also tends to keep oil. from splashing against the asket, thus minimizing any seepage of oil through the gasket in case of imperfect seal between the gasket and the case or cover.

The main cover 2 is also provided with a threaded hole 4'7 which is normally closed by a plug 48. The hole 47 so arranged and so located that oil may be pumped into or removed from the ease through this hole without removing the cover. Also water which may eccidentally get into the will collect in the bottom I of the case and may be pumped out through this hole, and the oil level may be determined by pushing a rod down through this hole to the bottom of this case. Furthermore, this hole permits a partial inspection of interior of the case to be made such, for example, as an examination for rust, sludge, etc,

The main cover 2 is further provided with a boss 49 (see Fig. 1) around the bottom of the hole 47 which is carried down to the level at which 1 near the inner it is desired to maintain the cooling medium. This boss, when the cooling medium is inserted into the case through the hole 47, causes an air pocket to be created between the cooling medium and the balance of the case as soon as the level of the oil reaches the bottom of the boss, which prevents excess fluid from being inserted, and insures plenty of room for expansion in the cooling medium with increases in temperature.

Formed on the outer surface of the main cover 2 are a plurality of upstanding projections 50, which as here shown are in the form of pyramids having diamond-shaped bases. One function of these projections is to render the outer surface of the cover non-skid, thus preventing workmen who may step on the cover from slipping thereon and injuring themselves.

The outer cover 2 is intended to protect the case and terminals from damage by dragging equipment or tampering and is bolted to lugs 48 (see Fig. 2) located at the corners of the case. This cover is normally left ofi of the case until after the bond has been installed.

With the bond constructed in the manner described, the terminal structures T1 and T3 comprise the rail terminals and the terminal structure T2 comprises the neutral terminal. It will be readily understood, therefore, that lightning surges coming in on the neutral terminal will pass from the shoulders 40 on the terminal post 29 of the terminal structure T2 to the case, and then to the shoulders 40 on the terminal post 29 of the terminal structures T1 and T3, and thence to the rails whch, being substantially in contact with the ground, allow the surge to be dissipated into the ground.

Although we have herein shown and described only one form of inductive bond embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims Without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is: v

1. The combination with a case containing an inductive bond and provided with terminal structures extending through the side of the case for making external electrical connections with the bond and with lugs projecting from the side of the case for fastening the case to a support, of a main cover secured to the case for sealing the case, and an auxiliary cover in the form of a ring around the outer edge of the main cover also secured to the case, said auxiliary cover being so designed that whe; said auxiliary cover is removed from said case free access to said lugs and said terminal structures is permitted but that when. said auxiliary cover is in place on said case access to said lugs and said terminal structures is prevented and the parts are protected from damage due to dragging railway equipment.

2. In combination, an inductive bond case provided with a tapered hole, a conical insulating bushing seated in said hole, a terminal post extending into said case through said bushing and provided with a tapered intermediate portion which fits the hole in said bushing and with a threaded end adjacent said tapered portion, a nut on said threaded portion for clamping said terminal post in place; a spring washer, a flat metal washer, and an insulating washer interposed between said nut and the adjacent wall of the case; and means on each end of said terminal post for securing electrical conductors to said terminal post.

3. In combination, an inductive bond case provided with a tapered hole, a conical insulating bushing seated in said hole, a terminal post extending into said case through said bushing and provided with a tapered intermediate portion which fits the hole in said bushing and with a threaded end adjacent said tapered portion, a nut on said threaded portion for clamping said terminal post in place, an insulating washer interposed between said nut and the adjacent wall of the case, and means on each end of said terminal post for securing electrical conductors to said terminal post.

4. In combination, an impedance bond case provided with a tapered and reamed hole, a conical insulating bushing seated in said hole, a terminal post extending into said case through said bushing, said terminal post being provided with a head at its outer end and a threaded portion at its inner end connected by an integral tapered portion which fits the bushing in said hole, a nut on said threaded portion for securely clamping said terminal post in place; a spring washer, a fiat metal washer, and an insulating washer interposed between said nut and the adjacent walls of the case in the order named; other nuts on the threaded portion of said terminal post for securing a conductor to the inner end of the terminal post, a threaded stud extending through the head of said terminal post and secured thereto, and nuts on each end of said stud for securing conductors to the outer end of said terminal post.

5. In combination, an impedance bond case provided with a tapered and reamed hole, a conical insulating bushing seated in said hole, a terminal post extending into said case through said bushing, said terminal post being provided with a head at its outer end and a threaded portion at its inner end connected by an integral tapered portion which fits the bushing in said hole, a nut on said threaded portion for securely clamping said terminal post in place; a spring washer, a flat metal washer, and an insulating washer interposed between said nut and the adjacent walls of the case in the order named, other nuts on the threaded portion of said terminal post for securing a conductor to the inner end of the terminal post, a threaded stud extending through the head of said terminal post and secured thereto, nuts on each end of said stud for securing conductors to the outer end of said terminal post, and rounded shoulders on the inner end of the head of said terminal post spaced a definite distance from said case to provide spark gaps which act as a lightning arrester.

6. An inductive bond comprising a magnetizable core having a leg surrounded by a winding, and means for fastening said winding in place on said core comprising a bolt extending through i engagement with one side of said winding and the other leg provided with an inclined slot which receives said bolt.

SAMUEL M. LUCAS. CONRAD H. ZIERDT. 

